JP2009538707A - Medical devices and related systems and methods - Google Patents

Abstract

Medical devices including a proximal tubular member, a distal tubular member, and an intermediate tubular member connecting the proximal tubular member to the distal tubular member, and related methods.

Description

  The present invention relates to medical devices and related systems and methods.

  Medical devices such as balloon catheters are used for various medical procedures. Balloon catheters are used to dilate occluded body vessels, for example, in angioplasty, to place endoprostheses such as stents or grafts, or to selectively block passageways can do. The balloon catheter can include an inflatable and deflated balloon disposed on a long and thin catheter body. Initially, the balloon is folded around the catheter body so that the radial profile of the balloon catheter is small for easy insertion into the body.

  During angioplasty, the folded balloon is placed in a guide catheter placed within the body vessel and at a location within the body vessel occluded by the stenosis by passing the balloon catheter over the guide wire. The balloon is then inflated, for example by introducing fluid into the balloon. The inflation of the balloon can widen the stenosis radially and increase the blood flow through the body vessel. After use, the balloon is deflated and removed from the body.

  The present invention seeks to provide medical devices and related systems and methods.

  In one aspect of the invention, a method of manufacturing a medical device includes disposing first and second tubular portions in an axially spaced arrangement within a cavity at least partially defined by a mold. Each of the first and second tubular members includes a lumen extending therein. Molten resin is delivered into the mold area between the first tubular member and the second tubular member. When cured, the resin forms an intermediate tubular member having a composition different from at least one of the first and second tubular members. The tip is disposed in the tip region of the medical device.

  In another aspect of the present invention, the medical instrument is joined to the proximal end tubular member, the distal tubular member, the distal end region of the proximal tubular member, and the proximal end region of the distal tubular member. Intermediate tubular member. The intermediate tubular member includes at least one material that is not thermally compatible with at least one material of the proximal and distal tubular members.

Embodiments can include one or more of the following features.
In some embodiments, the tip is secured to at least one of the first and second tubular members.
In some embodiments, the method further includes placing a mandrel in at least one of the lumens of the first and second tubular members.

In some embodiments, the mold includes at least one recessed region extending outwardly from and in communication with the cavity.
In some embodiments, the at least one recessed region includes a groove that extends circumferentially around the cavity.

In some embodiments, the recessed region includes a spiral groove.
In some embodiments, the mold includes a plurality of recessed areas spaced axially along the mold.
In some embodiments, the mold substantially prevents the first and second tubular members from axially moving relative to each other when the first and second tubular members are disposed within the mold. Configured to do.

In some embodiments, the resin has a melting temperature that is lower than the melting temperature of the first and second tubular members.
In some embodiments, the resin has a melting temperature that is higher than the melting temperature of the first and second tubular members.

In some embodiments, the method further includes heating the mold to a temperature below the melting temperature of the first and second tubular members.
In some embodiments, the method further includes heating the mold to a temperature below the melting temperature of the first and second tubular members, and the resin within the mold cavity before the resin is cooled and solidified. Including rapid infusion.

In some embodiments, the resin and at least one of the first and second tubular members are not thermally compatible.
In some embodiments, the method further includes disposing an intermediate tubular member in a predetermined region of the medical device. The predetermined region of the medical device is disposed within the predetermined region of the body vessel during use of the medical device.

In some embodiments, the predetermined region of the body tube includes a region of the body tube that is bent at an angle of at least about 70 degrees.
In some embodiments, the predetermined region of the body vessel includes a region where the aorta and the coronary artery are connected.

In some embodiments, the intermediate tubular member has a hardness that is less than the hardness of at least one of the first and second tubular members.
In some embodiments, the intermediate tubular member has a hardness that is higher than the hardness of at least one of the first and second tubular members.

In some embodiments, the predetermined region of the medical device is determined by measuring an axial distance from the tip region of the medical device.
In some embodiments, the method further includes removing material from at least one end region of each of the first and second tubular members. Each of the end regions includes a surface that extends at an acute angle to the longitudinal axis of the medical device after the material is removed.

In some embodiments, the method further comprises chemically bonding the resin to at least one of the first and second tubular members.
In some embodiments, the medical device includes a flexible tip that is secured to the tip region of the medical device.

In some embodiments, the flexible tip is secured to the distal tubular member.
In some embodiments, one of the proximal and distal tubular members includes a metal and the other includes a polymeric material.
In some embodiments, the intermediate tubular member includes at least one raised feature that extends from an outer surface of the intermediate tubular member.

In some embodiments, the at least one raised feature extends circumferentially around the intermediate tubular member.
In some embodiments, the at least one raised feature extends helically around the intermediate tubular member.

In some embodiments, the intermediate tubular member includes a plurality of raised features that are axially spaced along the intermediate tubular member.
In some embodiments, the raised features are spaced apart by gradually increasing the spacing from the proximal region of the intermediate tubular member toward the distal region of the intermediate tubular member.

In some embodiments, the at least one raised feature and the intermediate tubular member are integrally formed.
In some embodiments, the intermediate tubular member decreases in hardness from a proximal region of the intermediate tubular member toward a distal region of the intermediate tubular member.

In some embodiments, the intermediate tubular member has a hardness that is lower than the hardness of the proximal tubular member and higher than the hardness of the distal tubular member.
In some embodiments, the intermediate tubular member has a hardness that is less than the hardness of both the proximal and distal tubular members.

In some embodiments, the intermediate tubular member includes one or more therapeutic agents.
In some embodiments, the intermediate tubular member is chemically bonded to at least one of the proximal and distal tubular members.
In some embodiments, the intermediate tubular member is disposed in a predetermined region of the medical device, and the predetermined region of the medical device is disposed within the predetermined region of the body vessel during use of the medical device.

In some embodiments, the intermediate tubular member includes (eg, formed from) a fiber composite material, a clay composite material, a polymer blend, a polymer alloy, a curable polymer, and / or a crosslinkable polymer.

In some embodiments, the intermediate tubular member includes one or more additives (eg, clay, fibers, etc.).
Embodiments can include one or more of the following advantages.
In some embodiments, the medical device includes proximal and distal tubular members that include materials that are not compatible (eg, thermally incompatible). The method embodiments described herein allow such proximal and distal tubular members to be connected to one another via, for example, an intermediate tubular member.

  In certain embodiments, the intermediate tubular member is disposed at a predetermined location along the medical device. For example, the intermediate tubular member can be a flexible member that is configured to be placed in a tortuous region of the body vessel during use (eg, during deployment of an endoprosthesis). This design may help to improve the deployment accuracy of the endoprosthesis within the body vessel. Medical devices are similarly used in body tubes of various other shapes and sizes by disposing intermediate members at predetermined locations along the medical device that are placed in particular areas of the body tube during use. Can be tuned to work well.

  In some embodiments, the intermediate tubular member includes one or more raised features that extend from a surface (eg, an outer surface) of the intermediate tubular member. The raised features may be allowed to prevent kinking of the intermediate tubular member during use and / or to increase the radial strength of the intermediate tubular member and / or along the length of the intermediate tubular member. May help to change flexibility. Using the methods described herein, tubular members having raised features can be manufactured at low cost.

  In certain embodiments, the intermediate tubular member is more flexible than the proximal tubular member and less flexible than the distal tubular member. Thus, the intermediate tubular member is a flexible comparison between the proximal and distal tubular members, for example, compared to a design in which the proximal and distal tubular members are directly attached to each other (eg, by welding). Smooth transition can be provided. In some embodiments, the intermediate tubular member varies in flexibility along its length, thereby providing a smooth transition of flexibility between the proximal tubular member and the distal tubular member. It may help further to produce.

  In some embodiments, one or more physical properties (eg, hardness, flexibility) of the intermediate tubular member can be altered by changing the amount of shear applied to the resin. For example, as the amount of shear applied to the resin increases, the resin (eg, polymer resin) may degrade and the hardness may decrease. Thus, the hardness of the intermediate tubular member can be varied along the length of the intermediate tubular member by changing the amount of shear applied to the resin delivered to the molding apparatus. As an example, a single resin composition can be used to create a gradient (eg, a hardness gradient) along the length of the intermediate tubular member.

  In certain embodiments, the proximal and distal tubular members (eg, the distal region of the proximal tubular member and the proximal region of the distal tubular member) are pretreated to provide an intermediate tubular member and a proximal tubular member. Better adhesion between the member and the distal tubular member is provided. In some embodiments, pretreatment of the proximal and distal tubular members includes functionalizing the surfaces of these tubular members.

  Other aspects, features, and advantages of the invention will be apparent from the description and drawings, and from the claims.

  In general, a medical device includes a proximal tubular member, a distal tubular member, and an intermediate member connecting the proximal tubular member and the distal tubular member. The proximal and distal tubular members can include materials that are not thermally compatible (eg, formed of such materials). A method of manufacturing a medical device includes: disposing a part of a proximal end side member and a distal end side tubular member in an axial direction apart from each other in a mold; and a mold between the proximal end side tubular member and the distal end side tubular member. Injecting molten resin into the interior space.

  Referring to FIG. 1, the balloon catheter 100 includes an inner catheter shaft 105 and an outer catheter shaft 110. The inner catheter shaft 105 includes a proximal tubular element 115, a distal tubular element 120, and an intermediate tubular element 125 that connects the proximal tubular element 115 to the distal tubular element 120. Balloon 127 is attached to distal region 130 of distal tubular element 120 and distal region 135 of outer catheter shaft 110. A flexible tip 137 is also attached to the tip region 130 of the inner catheter shaft 105 near the tip of the balloon 127. As shown in FIG. 2, the inner catheter shaft 105 and the outer catheter shaft 110 that extends coaxially about and around the inner catheter shaft 105 have a generally circular cross-sectional shape. Guidewire lumen 140 extends into inner catheter shaft 105 and annular inflation lumen 145 extends along catheter 100 between inner catheter shaft 105 and outer catheter shaft 110. As shown in FIG. 1, the stent 150 can be wound on the outer surface of the balloon 127.

  In certain embodiments, proximal element 115 (eg, one or more materials of proximal element 115) is compatible with distal element 120 (eg, one or more materials of distal element 120). Not compatible (for example, thermally incompatible). One of the proximal and distal elements 115 and 120 may degrade before the other element reaches its softening or melting point. Both elements may have melting points that differ to the extent that they make it impractical or impossible to make (eg, by welding both elements). For example, the proximal element 115 has a melting temperature of the distal element 120 of at least about 15 ° C. (eg, at least about 25 ° C., at least about 50 ° C., at least about 75 ° C., at least about 100 ° C., at least about 125 ° C., at least It can have a different melting temperature by about 150 ° C). In certain embodiments, the melting temperature of the proximal element 115 is about 160 ° C. or less (eg, about 150 ° C. or less, about 125 ° C. or less, about 100 ° C. or less, about 75 ° C. or less) with the melting temperature of the distal element 120. , About 50 ° C. or less, about 25 ° C. or less). The melting temperature of the proximal and distal elements 115, 120 can vary, for example, by about 15 ° C to about 160 ° C (eg, about 50 ° C to about 100 ° C).

  Instead of or in addition to being thermally incompatible, the materials of the proximal and distal elements 115 and 120 may be otherwise incompatible with each other. In certain embodiments, for example, the materials are not chemically compatible. As an example, one of the proximal and distal elements 115, 120 can be formed from a hydrophilic material such as nylon 12 and the other can be formed from a hydrophobic material such as low density polyethylene (LDPE). it can. For example, one of the proximal and distal elements 115, 120 can be formed from a material such as PVC and / or CPVC that is typically degraded by thermal bonding techniques, and the other can withstand thermal bonding techniques. It can be formed from one or more materials. In some embodiments, the proximal element 115 and / or the distal element 120 is a wire mesh (eg, a stainless steel wire mesh) that tends to exacerbate degradation caused by certain heat-related joining techniques. Including.

  Due to the material incompatibility of the proximal and distal elements 115 and 120, it is difficult to directly bond these elements using specific attachment techniques that utilize heat, such as thermal bonding and / or laser bonding. It will be. However, in some embodiments, the intermediate element 125 includes one or more materials that are compatible with the material of both the proximal element 115 and the distal element 120. In such embodiments, the intermediate element 125 can be coupled to the proximal and distal elements 115 and 120, respectively, regardless of the incompatibility of the proximal and distal elements 115 and 120 with respect to each other, thereby. The proximal and distal elements 115 and 120 are coupled along the inner catheter shaft 105.

  In a particular embodiment, as shown in FIG. 4, the distal end 155 of the proximal element 115 and the proximal end 160 of the distal element 120 are tapered. As a result, the surface area of the joining areas 156 and 161 between the intermediate element 125 and the proximal element 115 and between the intermediate element 125 and the distal element 120 is increased compared to the joining area between the non-tapered shafts. can do. An increase in the surface area of the bonding region can contribute to an improvement in bonding strength. As such, the bond between the intermediate element 125 and the proximal element 115 and the distal element 120 can be relatively stronger compared to the bond that occurs between two non-tapered tubular members.

  In some embodiments, the intermediate element 125 is more flexible than the proximal element 115 and less flexible than the distal element 120. Therefore, the intermediate element 125 can contribute to a smooth transition of flexibility between the relatively rigid proximal element 115 and the relatively flexible distal element 120, and this This may contribute to preventing kinking and / or buckling of the inner shaft 105 during use. In some embodiments, for example, the intermediate element 125 has a hardness that is lower than the hardness of the proximal element 115 and higher than the hardness of the distal element 120. The intermediate element 125 may have a hardness that is about 20D to about 40D lower than the hardness of the proximal element 115 and about 40D to about 50D higher than the hardness of the distal element 120, for example. Alternatively or in addition, the wall thickness of the intermediate element 125 may be different from the wall thickness of the proximal element 115 and / or the distal element 120. In certain embodiments, for example, the wall of the intermediate element 125 is thinner than the wall of the proximal element 115 and / or thicker than the wall of the distal element 120. For example, the wall of the intermediate element 125 is about 0.07 millimeters to about 0.12 millimeters thinner than the wall of the proximal element 115 and / or about 0.07 millimeters to about 0.00 mm from the wall of the distal element 120. 12mm thick.

  In certain embodiments, the intermediate element 125 is chemically bonded to one or both of the proximal and distal elements 115 and 120. For example, the intermediate element 125 can be cured (eg, when exposed to ultraviolet energy) a curable adhesive that can be chemically bonded to one or both of the proximal and distal elements 115 and 120 (eg, UV curable adhesive). Examples of adhesives include epoxies, phenols, urethanes, anaerobic adhesives, acrylics, cyanoacrylates, silicones, polysulfides, and elastic adhesives.

  The intermediate element 125 and the proximal and distal elements 115 and 120 maintain continuous bending properties and do not collapse during use or narrow and can be coated with a lubricious material; It can include materials that have good tensile strength and / or can be sterilized. In certain embodiments, the intermediate element 125 comprises a microfiber composite, alloy, or mixed material. The intermediate element 125 is, for example, polyurethane, polyether amide, polybutyrate, polyvinyl butyrate, polyacrylonitrile, acrylonitrile-butyrate-acetate (ABS) tripolymer, polyacetate, polyvinyl acetate, PVC, CPVC, FEP, PTFE, polyacetal, polyolefin 1 such as polyamides (eg nylon 12, nylon 11, nylon 6/12, nylon 6, and nylon 66), polyesters, polyethers, polyureas, polyvinyls, polyacryls, fluoropolymers, and copolymers and block copolymers thereof. One or more polymers can be included. The intermediate element 125 may comprise a block copolymer of polyether and polyamide, such as, for example, Pebax® (eg, Pebax® having a relatively high durometer value such as 50). In some embodiments, the intermediate element 125 comprises clay, silica, or metal nanocomposite.

  In some embodiments, the intermediate element 125 includes one or more crosslinkers. The cross-linking agent can increase the strength, flexibility, and / or extensibility of the intermediate element 125. The intermediate element 125 can have a different material composition than the proximal and / or distal elements 115, 120.

  Proximal element 115 and / or distal element 120 can include one or more polymeric materials. Examples of polymeric materials include thermoplastic materials and thermosetting materials. Examples of thermoplastic materials include, for example, polyolefins, polyamides (such as nylon 12, nylon 11, nylon 6/12, nylon 6, and nylon 66), polyesters, polyethers, polyurethanes, polyureas, polyvinyls, polyacryls, fluoropolymers, These copolymers and their block copolymers (polyether and polyamide block copolymers such as Pebax® (eg Pebax® having a relatively high durometer value such as 50)), mixed materials Can do. Examples of thermoset materials include elastomers such as EPDM, epichlorohydrin, nitrile butadiene elastomer, silicone and the like. Conventional thermosetting materials such as epoxies, isocyanates and the like can also be used. Biocompatible thermosetting materials such as biodegradable polycaprolactone, poly (dimethylsiloxane) containing polyurethane and urea, and polysiloxane can also be used. One or more of these materials can be used in any combination.

  Other polymeric materials include, for example, elastomers such as thermoplastic elastomers, and engineering thermoplastic elastomers such as polybutylene terephthalate-polyethylene glycol block copolymers sold as HYTREL®. Elastomers are described, for example, in Hamilton US Pat. No. 5,797,877, which is hereby incorporated by reference in its entirety. Other polymers include liquid crystal polymers (LCP). Examples of LCPs include polyesters, polyamides, and / or copolymers thereof, such as VECTRA® A (Ticona), VECTRA® B (Ticona), and VECTRA® LKX. (Made by Ticona) (for example, VECTRA (registered trademark) LKX1111 (made by Ticona)). Alternatively or additionally, the proximal element 115 and / or the distal element 120 may be steel, aluminum, titanium, platinum, gold, copper, zinc, iron, bismuth, barium, and / or One or more metals such as one or more salts of metals can be included.

  In some embodiments, the proximal element 115 includes (eg, formed from) the same type of material or combination of materials as the distal element 120. Alternatively, the proximal element 115 can include a different type of material or combination of materials than the distal element 120 (eg, can be formed from the material). In certain embodiments, for example, proximal element 115 includes one or more nylons, such as nylon 12, and distal element 120 includes one or more polyether block amides, such as Pebax. In such embodiments, the intermediate element 125 can include one or more polyurethanes that can be bonded (eg, chemically bonded) to both nylon and polyether block amide.

  The dimensions of the proximal element 115, the distal element 120, and the intermediate element 125 can be varied depending on the intended use of the balloon catheter. For example, the length of the element can be changed. In some embodiments, the intermediate element 125 is shorter than the proximal element 115 and / or the distal element 120. In certain embodiments, the intermediate element 125 is longer than the proximal element 115 and / or the distal element 120. In certain embodiments, the intermediate element is about 0.5 centimeters to about 20 centimeters (eg, about 1 centimeter to about 5 centimeters, about 5 centimeters to about 10 centimeters, about 10 centimeters to about 10 centimeters). 20 centimeters).

  5A-5D illustrate one embodiment of a method for manufacturing the inner catheter shaft 105 of the balloon catheter 100. FIG. As shown in FIG. 5A, the method begins with a tubular member 200. As shown in FIG. 5B, material is removed from the circumferential end region 205 of the tubular member 200 to form the proximal inner element 115. Material removed from the end region 205 of the tubular member 200 may be removed using one or more material removal techniques such as centerless grinding, cryogenic grinding, machining, skiving, laser ablation, and the like. it can. While removing material from the tubular member 200, a support member (eg, a steel shaft coated with polytetrafluoroethylene) can be placed in the lumen 202 of the tubular member 200. The support member can contribute to stabilizing the tubular member 200 during the material removal process. In certain embodiments, the support member can rotate the tubular member 200 during the material removal process to help ensure that the material is evenly removed at the circumferential surface of the tubular member 200. As an alternative or in addition to removing material from the tubular member 200, the tubular member 200 can be formed into a desired shape (eg, a desired shape for the proximal inner element 115).

  Proximal inner element 115 includes a taper 117 with material removed from tubular member 200 at the end (eg, the distal end of proximal inner element 115), as shown in FIG. 5B. Taper 117 provides a bonded area with increased surface area. Instead of, or in addition to, taper 117, material can be removed from the end of tubular member 200 to form other shapes that provide increased surface area that can be joined to another tubular member. . For example, the material can be removed to provide an end region having a double taper (eg, an end region that tapers inwardly from the outer surface and tapers outwardly from the inner surface). In another example, the ends can have a notched shape or a bead shape to facilitate mechanical engagement of adjacent elements.

  A second tubular member (not shown) is also provided and material is similarly removed from the end region of the second tubular member to form the distal inner element 120. Material can be removed from the end region of the second tubular member using one or more of the material removal techniques previously described.

  After forming the proximal and distal elements 115 and 120 from the respective tubular members, the proximal and distal elements 115 and 120 are coated with a mandrel (eg, polytetrafluoroethylene, as shown in FIG. 5C). (Steel shaft) 207. Proximal and distal elements 115 and 120 can be disposed in an axially spaced relationship along the mandrel 207. The mandrel 207 can structurally support the proximal and distal elements 115 and 120 during the molding process.

  FIG. 5D shows a cross-sectional view of the molding apparatus 210 including the cover 215 and the base 220. When cover 215 is closed as shown in FIG. 5D, cover 215 and base 220 define a passage 225 therebetween, in which mandrel 207 and proximal and distal elements 115 and 120 are defined. A part of can be inserted. Cover 215 includes an inlet passage 245 and an outlet passage 250 that both communicate with passage 225. The molding apparatus 210 can include one or more materials having a relatively high melting temperature (eg, can be formed from such materials). For example, the forming device 210 can include one or more metals such as 440C stainless steel, copper, and / or brass. Alternatively or in addition, the forming apparatus includes one or more ceramics and / or one or more glasses, such as silica glass (eg, Pyrex®) or sapphire glass. be able to. In certain embodiments, the inner surface of the molding device 210 (eg, the surface defining the passage 225) is lined with a low friction material such as PTFE, so that the catheter shaft molded in the molding device 210 is molded after molding. Can be easily removed.

  In some embodiments, the molding apparatus 210 is temperature controlled. For example, the molding device 210 can include one or more cooling tubes connected to a high temperature cooling device, such as a refrigerator or refrigerant. Alternatively or in addition, the molding apparatus 210 can include a series of cooling fins with an appropriately sized forced convection device (eg, a fan or blower). In some embodiments, the molding apparatus 210 is surrounded by a temperature control jacket, such as an insulated high pressure steam jacket and / or a hot oil jacket. In certain embodiments, the molding apparatus 210 is heated by RF induction heating and cooled by forced convection. The molding device 210 can be heated and / or cooled to help regulate the temperature of the molding device.

  As shown in FIG. 5E, the proximal inner element 115 is disposed in the proximal region of the passage 225 in the molding device 210, and the distal inner element 120 is in the distal region of the passage 225 in the molding device 210. Placed inside. The proximal and distal elements 115 and 120 are disposed in the molding apparatus 210 such that the distal end 119 of the proximal inner element 115 is axially spaced from the proximal end 122 of the distal inner element 120. For example, the proximal and distal elements 115 and 120 can be spaced from each other within the molding apparatus 210 by a distance approximately equal to the length desired for the intermediate element 125. After the proximal and distal inner elements 115 and 120 are placed in the molding apparatus 210 as desired, the cover 215 of the molding apparatus 210 is closed so that the proximal and distal elements 115 and 120 are respectively Fixed to the axial position. For example, the cover 215 and base 220 of the molding apparatus 210 compress the proximal and distal elements 115 and 120 between the cover 215 and the base 220 when the cover 215 is closed, thereby causing the proximal inner element 115 and The distal inner elements 120 can be held in a substantially axially fixed position relative to each other. Alternatively or in addition, the proximal and distal elements 115 and 120 may be secured axially by creating a negative pressure in the outlet passage 250 so that the proximal and A net inward thrust is generated for the tip elements 115 and 120.

  A tubular cavity 235 is formed in the passage 225 between the proximal element 115 and the distal element 120 and around the mandrel 207. As described below, the intermediate tubular member 125 can be molded within the cavity 235. Thus, the proximal and distal elements 115 and 120 can be positioned closer or further away along the mandrel 207 depending on the length desired for the intermediate element 125. Similarly, the shape of the forming device 210 (eg, the shape of the forming device 210 of the portion defining the cavity 235) may be selected and / or changed based on the size and shape desired for the intermediate element 125. it can. In some embodiments, the inner surface of the molding device 210 is lined with a non-stick material such as PTFE to facilitate removal of the intermediate element 125 from the cavity 235 after being molded in the molding device 210.

  Referring to FIG. 5F, after the cover 215 is closed and the proximal and distal elements 115 and 120 are axially secured, molten resin 240 is injected into the tubular cavity 235 via the inlet passage 245. As the resin 240 is injected into the cavity 235 through the inlet passage 245, air in the cavity 235 can escape through the outlet passage 250. Alternatively or in addition, air may be exhausted from cavity 235 via outlet passage 250 (eg, by applying a negative pressure to outlet passage 250) prior to injection of resin 240. In certain embodiments, the inlet passage 245 and / or the outlet passage 250 is used to introduce an inert gas such as nitrogen and / or argon into the cavity 235. Resin 240 is injected into cavity 235 until cavity 235 is substantially filled (eg, about 98% or more of the volume of cavity 235 is filled with resin). In certain embodiments, the cavity 235 is overfilled (eg, overfilled). In such an embodiment, excess resin can enter the outlet passage 250.

  Depending on the composition of the resin 240 and the proximal and distal elements 115 and 120, the resin 240 can be injected at a variety of different temperatures, pressures, and flow rates. In some embodiments, resin 240 is injected into tubular cavity 235 at a temperature of about 80 ° C. to about 500 ° C., a pressure of about 300 kPa to about 35000 kPa, and / or a flow rate of about 1 ml / min to about 1000 ml / min. Is done.

  When injected into the cavity 230, the resin 240 may have a viscosity of about 4500 Pa · s or less (eg, about 3500 Pa · s or less, about 2500 Pa · s or less, about 1500 Pa · s or less, about 1000 Pa · s or less). it can. In certain embodiments, the resin 240 has a viscosity of about 500 Pa · s to about 4500 Pa · s (eg, about 1000 Pa · s to about 3500 Pa · s, about 1500 Pa · s to about 2500 Pa · s). For example, the resin 240 may be heated before being injected into the cavity 235 until a target viscosity is reached. The resin 240 can include one or more of the materials described herein with respect to the intermediate element 125.

  After the cavity 235 is filled with resin 240, the resin and proximal and distal elements 115 and 120 are maintained at the mold temperature for a predetermined residence time. The mold temperature can range from about 130 ° C to about 230 ° C. The predetermined residence time may be a time sufficient to complete the bonding between the resin 240 and the proximal end element 115 and the distal end element 120. In some embodiments, the predetermined period ranges from about 1 second to about 30 seconds.

  After cavity 235 is filled with resin 240 and maintained at a high temperature for a predetermined residence time, the resin cools and solidifies. In certain embodiments, as described above, a cooling device such as a steam jacket can be used to control (eg, increase) the rate at which the resin cools. The cooling time can range from about 5 seconds to about 2 minutes. In certain embodiments, as an intermediate step in the cooling process, molding apparatus 210 is maintained at a predetermined temperature (eg, about 90 ° C. to about 150 ° C.) to facilitate annealing of solidified resin 240. The resin 240 in the cavity 235 forms the intermediate element 125 of the inner shaft 105 when solidified. Inner shaft 105 can be connected to outer shaft 110 and balloon 127 of balloon catheter 100 using one or more joining techniques, such as laser joining and / or gluing.

  3A-3E show how the balloon catheter 100 is used. Referring to FIG. 3A, the method inserts a guide wire 165 into a body vessel 170 (eg, a blood vessel) and then places the guide wire 165 within the guide wire lumen 140 of the inner catheter shaft 105. As shown, the balloon catheter 100 is advanced over the guide wire 165. The balloon catheter 100 is then advanced along the guidewire 165 and into the body tube 170 until the deflated balloon 127 and the stent 150 are finally shown in the occluded region 175 of the body tube 170 as shown in FIG. 3B. Placed inside. After placement within the occlusion region 175 of the body tube 170, the balloon 127 is inflated to deploy the stent 150 within the body tube 170, as shown in FIG. 3C. Balloon 127 can be expanded by flowing an inflation fluid, such as saline, through annular inflation lumen 145. For example, an inflation mechanism such as a syringe may be connected to the proximal end (not shown) of the balloon catheter 100 to send inflation fluid to the balloon 127. Expansion of the balloon 127 and deployment of the stent 150 can contribute to radial expansion of the occlusion 175 and / or radial support in that region of the body tube 170. When the stent 150 is deployed, the balloon 127 is deflated and the balloon catheter 100 is withdrawn from the body tube 170, as shown in FIGS. 3D and 3E.

Although various embodiments have been described, other embodiments are possible.
By way of example, in some embodiments, the flexibility of the intermediate element 125 varies along its length. For example, in order to increase the followability of the catheter, the intermediate element 125 can become increasingly flexible from its proximal end to the distal end. The intermediate element 125 can be formed to become increasingly flexible along the length of the intermediate element 125, for example, by changing the composition of the resin 140 delivered through the inlet passage 145. Alternatively or additionally, the wall of the intermediate element 125 can be progressively thinner from the proximal end to the distal end of the intermediate element. Increasingly thinner walls can be formed, for example, by changing the configuration of the cavity 235 and / or the mandrel 207.

  In another example, in certain embodiments, intermediate element 125 is more flexible than proximal and distal elements 115 and 120. The intermediate element 125 can be placed in a catheter area that greatly deflects during use. For example, the intermediate element 125 can be placed in a catheter region that is placed in a tortuous region of the body vessel during use (eg, at the junction of the aorta and coronary artery). The relatively high flexibility of the intermediate element 125 can contribute, for example, to an improvement in the ability of the catheter to be placed and / or passed through tortuous regions of the body vessel. The intermediate element 125 can include one or more materials that are more flexible than the material of the proximal and distal inner elements 115 and 120 (eg, can be formed from one or more materials). it can). In certain embodiments, the intermediate element 125 includes one or more materials that are softer than the material of the proximal and distal inner elements 115 and 120. For example, the intermediate element 125 can have a hardness that is about 10D to about 40D less than the hardness of the proximal and distal inner elements 115 and 120. For example, the intermediate element 125 can have a hardness of about 30D to about 55D. Alternatively or in addition, the intermediate element 125 may be formed with a thinner wall than the proximal element 115 and / or the distal element 120.

  By way of further example, in some embodiments, one or more therapeutic agents are carried by the intermediate element 125 (eg, carried within the intermediate element 125). Certain therapeutic agents can, for example, reduce the convulsive response during balloon angioplasty. The therapeutic agent is carried on the intermediate element 125 using one or more techniques, such as premixing the therapeutic agent with the resin of the intermediate element 125 and / or coating the intermediate element 125 with the therapeutic agent. be able to. Examples of therapeutic agents include paclitaxel, oxybutynin, belladonna alkaloids, phenobarbital, non-steroidal anti-inflammatory drugs, and heparin.

  As a further example, in some embodiments, the material is embedded in the intermediate element 125 during the molding process. For example, a conductor (eg, knitted or rolled conductive wire) can be embedded in the intermediate element 125. For example, the conductor is placed in the tubular cavity 235 such that at least a portion of the conductor is captured within the resin 240 when the resin 240 is injected into the molding apparatus 210 during the molding process shown in FIGS. 5E and 5F. can do. As another example, reinforcing elements such as glass fiber strands, metal fibers, and / or ceramic fibers may also be used as intermediate elements by placing reinforcing elements in the tubular cavity 235 prior to injecting the resin 240 into the tubular cavity 235. 125 can be embedded. The conductor and the reinforcing element can contribute to the improvement of the strength of the intermediate element 125 (for example, the improvement of the radial strength).

  In another example, the intermediate element can be placed at a location along the balloon catheter that is predetermined to be placed in a tortuous region of the blood vessel during use (eg, during stent deployment). The tortuous region of the blood vessel can have one or more regions that bend, for example, at an angle of at least about 70 ° (eg, at least about 90 °, about 70 ° to about 110 °). This placement of the intermediate element along the catheter is, for example, a property that allows the intermediate element to be more easily placed within a tortuous region of the body vessel compared to the proximal and / or distal element (eg, possible). It may be advantageous if it has a flexibility level. To determine the position along the balloon catheter where the intermediate element should be located, first the area of the body vessel where the balloon catheter is used is imaged using techniques such as X-ray imaging, fluoroscopy, or magnetic resonance imaging be able to. Determining a desired distance between a body vessel region to be treated (eg, an occlusion region) and a body vessel region (eg, a tortuous region) where an intermediate element is to be placed based on an image of the body vessel it can. The balloon catheter can then be formed such that the intermediate element is spaced from the balloon by a distance approximately equal to the distance between the body vessel region to be treated and the tortuous region of the body vessel.

  FIG. 6 illustrates the use of a balloon catheter 300 that includes an inner catheter shaft 305 and an outer catheter shaft 310. Inner catheter shaft 305 includes an intermediate element 325 that is positioned in place along the balloon catheter to fit within the tortuous or bent region 180 of body tube 170 during use. For example, the intermediate element 325 can be configured to be placed at the junction of the patient's aorta and coronary artery during use. The intermediate element 325 is joined in the axial direction between the proximal element 315 and the distal element 320 which are less flexible. When balloon 327 and stent 150 are placed as desired (eg, within the occluded region of body tube 170), intermediate element 325 provides a tortuous or bent region 180 (eg, aorta into coronary artery) of body tube 170. Adjacent to the area to be connected. Because the intermediate element 325 is more flexible than the proximal and distal elements 315 and 320, the intermediate element 325 is relatively well adapted to the shape of the bend of the body vessel. Therefore, this configuration can contribute to improving the mobility of the catheter within the torsional body vessel. In some embodiments, the configuration can contribute to the placement of balloon 327 and stent 150 with improved accuracy. For example, the balloon 327 and the stent 150 can be maintained at a substantially central position of the body tube 170 during use regardless of the presence or absence of the bent portion 180. This arrangement can contribute to the improvement of the deployment accuracy of the stent 150 in the body vessel.

  As a further example, the intermediate element of the above-described embodiment includes a substantially uniform outer surface along its length, but in certain embodiments, the intermediate element may include a raised feature extending from the surface. it can. As shown in FIG. 7, for example, the intermediate element 425 can be corrugated. In this embodiment, the intermediate element 425 includes a raised feature 430 that extends inwardly from the inner surface 435 and outwardly from the outer surface 440. The corrugated shape of the intermediate element 425 can help to prevent the intermediate element 425 from kinking during use.

  The corrugated intermediate element 425 can be molded using a method similar to that described above. The forming apparatus can include a corrugated inner surface corresponding to the desired corrugated surface for the intermediate element 425. The molding apparatus can include, for example, a central passage and a plurality of recessed areas extending outward from the central passage and communicating with the central passage. The tubular body of the intermediate element 425 can be formed in a mold passage and the raised features can be formed in a recessed region extending outwardly from the passage.

  Referring to FIG. 8, as another example, the intermediate element 525 includes an annular ring 530 that extends circumferentially around the outer surface 540 of the intermediate element 525. In certain embodiments, as shown in FIG. 8, the annular ring 530 can be spaced at approximately equal intervals along the intermediate element 525, contributing to increased strength of the intermediate element 525. In certain embodiments, the annular ring 530 can be spaced apart with varying spacing along the intermediate element 525. For example, the annular ring 530 may gradually increase in spacing from the proximal end 545 of the intermediate element 525 toward the distal end 550 of the intermediate element 525. As a result, the intermediate element 525 can decrease in rigidity from the proximal end 545 toward the distal end 550. Instead of, or in addition to, the annular ring, the intermediate element can include a raised helical member that extends along the outer surface of the element.

  The intermediate element 525 can be molded in a molding apparatus as described above. The molding apparatus can include, for example, a central passage and a plurality of recessed areas extending outward from the central passage and communicating with the central passage. The tubular body of the intermediate element 525 can be formed in a mold passage, and the raised features can be formed in a recessed region extending outwardly from the passage.

  As a further example, the above-described embodiments have described an intermediate element having a substantially circular cross-sectional shape, but the intermediate element may have other cross-sectional shapes instead of or in addition to this cross-sectional shape. Can do. As shown in FIG. 9, for example, the intermediate element 625 has a substantially elliptical cross-sectional shape. Referring to FIG. 10, the intermediate element 725 has an octagonal cross-sectional shape. The intermediate element 825 has a square cross-sectional shape as shown in FIG. The intermediate element 925 has a substantially star-shaped cross section as shown in FIG. An intermediate element having a non-circular cross-sectional shape can be formed by using a forming device that includes a non-circular forming passage or cavity and / or a mandrel having a non-circular cross-sectional shape. In some embodiments, an intermediate element having a non-circular cross-sectional shape can contribute to a reduction in the amount of friction caused by the outer tubular member of the catheter sliding relative to the inner tubular member of the catheter.

  As another example, while the above-described embodiments have described specific materials that can be the forming material of the proximal element 115, the distal element 120, and the intermediate element 125, these elements are described herein. Any of the materials described in can be formed using a variety of different combinations. For example, one or more of the materials described herein with respect to the proximal and distal elements 115, 120 can be used to form the intermediate element 125, and vice versa.

  As a further example, while the above-described embodiments have been described for an instrument that includes a single intermediate element between a proximal element and a distal element, in some embodiments, the instrument is a proximal element. A plurality of (for example, two or more, three or more, four or more, five or more) intermediate elements disposed between the front end side elements are included. Referring to FIG. 13, for example, the catheter shaft includes first and second intermediate elements 125, 1025 disposed between the proximal element 115 and the distal element 120. In certain embodiments, intermediate elements 125 and 1025 have different material compositions. In some embodiments, intermediate element 125 is more compatible with proximal element 115 than intermediate element 1025 (eg, thermally and / or chemically more compatible) The element 1025 is more compatible with the distal element 120 than the intermediate element 125. Thus, by using both intermediate elements, not just one intermediate element, the degree of bonding between the various elements of the catheter shaft can be increased. The catheter shaft can be formed using one or more techniques similar to those described above with respect to the balloon catheter 100. Intermediate elements 125 and 1025 can be formed, for example, by injecting two different resin streams into the molding apparatus.

  As a further example, the above-described embodiments relate to the inner catheter shaft of a balloon catheter, but other elements of the balloon catheter can alternatively or in addition be similar to those described above for the inner shaft. The integrally formed proximal element, distal element, and intermediate element can be included. In some embodiments, for example, the outer shaft includes an integrally formed proximal element, distal element, and intermediate element. In certain embodiments, both the inner and outer shafts include such a configuration. In some embodiments, the intermediate element of the outer shaft is axially disposed along the balloon catheter in approximately the same region as the intermediate element of the inner shaft. In certain embodiments, the intermediate element of the outer shaft is positioned along a region of the outer shaft that is predetermined to be positioned adjacent to the tortuous region of the body vessel during use. Alternatively or in addition, the intermediate element of the outer shaft can be arranged at other positions along the outer shaft.

  By way of further example, the embodiments described above relate to balloon catheters, but other types of medical devices can similarly include one or more tubular members or shafts as described herein. Examples of other types of medical devices are self-expanding stent delivery systems (eg, inner members of self-expanding stent delivery systems, outer sheaths of self-expanding stent delivery systems), guide catheters, endoscopes, cardiac rhythm management (CRM) Conductive wire, urine drainage device, postoperative wound drainage device, and stomach feeding tube.

The following example illustrates a process for manufacturing a catheter shaft.
(Example 1)
To form the catheter shaft, a proximal tubular segment formed from nylon 12 and a distal tubular segment formed from Pebax 7033 are provided. The proximal tubular segment has an outer diameter of about 0.045 inches (about 1.14 millimeters) and an inner diameter of about 0.038 inches (about 0.965 millimeters). The distal tubular segment has an outer diameter of about 0.028 inches (about 0.711 millimeters) and an inner diameter of about 0.024 inches (about 0.610 millimeters).

  Using a known skiving process, a taper is formed on the proximal region of the distal tubular segment and on the distal region of the proximal tubular segment. For each segment, an approximately 1 centimeter portion of the shaft is skived. After skiving, the end region of the tubular segment is trimmed to obtain a tapered region having a length of 1 centimeter.

  After forming tapered regions on the proximal and distal tubular segments, a steel mandrel coated with PTFE is inserted into the central lumen of the proximal and distal tubular segments. The coated mandrel is tapered to allow a small inner diameter of the distal segment and a larger inner diameter of the proximal segment. The mandrel includes indicia that are dyed to help the technician accurately place each of the segments on the mandrel. A steel mandrel coated with PTFE is configured to extend distally beyond the distal segment when the proximal and distal segments are properly positioned on the mandrel. This configuration contributes to facilitating removal of the mandrel after completion of the molding procedure described below.

  After placing the proximal and distal tubular segments on the mandrel, an assembly consisting of the proximal segment, the distal segment, and the mandrel is placed on the lower mold of the open mold. The mold forms a cavity when closed. There is one injector gate at the top of the mold and two outlet gates at the bottom of the mold. One of the exit gates is at the tip of the mold and the other is at the base end of the mold. The inner part of the mold is coated with a non-stick surface such as PTFE. The mold forming material is UV transmissive.

  When the assembly consisting of the distal segment, the proximal segment, and the mandrel is placed on the lower mold of the opened mold, the mold is closed and a clamping force of about 500 pounds (about 227 kilograms) is applied to the mold. Added evenly. The inner diameter of the closed mold defining the cavity is about 0.0015 inches (about 0.038 millimeters) less than the outer diameter of the proximal and distal tubular segments. Thus, the proximal and distal tubular segments are secured by a closed mold. The mold is then heated to 110 ° C., a negative pressure of about 50 millimeters of mercury is applied to the exit gate, and all air is exhausted from the cavity formed by the closed mold. A UV curable epoxy (eg, Masterbond UV15-7SP4DC) is then injected into the mold cavity at a temperature of 110 ° C. The injection time is about 3 seconds. After injecting the UV curable epoxy into the mold, the mold is irradiated with ultraviolet light for 1 minute to start the curing process. The mold temperature is then raised to 120 ° C. in 5 minutes so that the epoxy can cure, thereby forming the middle segment of the catheter shaft. The assembly is then removed from the mold and placed in the chamber for controlled curing of the intermediate segment.

  The outer surface of the middle segment contains a shallow corrugation. The inner diameter of the intermediate segment is linearly tapered from 0.038 inch (0.965 millimeter) to 0.024 inch (0.610 millimeter). The length of the middle segment is about 8 centimeters long.

  Other embodiments are within the scope of the appended claims.

1 is a cross-sectional view of one embodiment of a balloon catheter. Sectional drawing in the 2-2 line of FIG. The figure which shows one Embodiment of the usage method of the balloon catheter of FIG. The figure which shows one Embodiment of the usage method of the balloon catheter of FIG. The figure which shows one Embodiment of the usage method of the balloon catheter of FIG. The figure which shows one Embodiment of the usage method of the balloon catheter of FIG. The figure which shows one Embodiment of the usage method of the balloon catheter of FIG. The enlarged view of the area | region 4 of FIG. The figure which shows one Embodiment of the manufacturing method of the catheter shaft of the balloon catheter of FIG. The figure which shows one Embodiment of the manufacturing method of the catheter shaft of the balloon catheter of FIG. The figure which shows one Embodiment of the manufacturing method of the catheter shaft of the balloon catheter of FIG. The figure which shows one Embodiment of the manufacturing method of the catheter shaft of the balloon catheter of FIG. The figure which shows one Embodiment of the manufacturing method of the catheter shaft of the balloon catheter of FIG. The figure which shows one Embodiment of the manufacturing method of the catheter shaft of the balloon catheter of FIG. 1 is a diagram illustrating one embodiment of a balloon catheter in use. Sectional drawing of one Embodiment of the tubular member containing a protruding shape part. FIG. 3 is a cross-sectional view of one embodiment of a tubular member that includes different raised features. The figure which shows one Embodiment of the tubular member which has various different cross-sectional shapes. The figure which shows one Embodiment of the tubular member which has various different cross-sectional shapes. The figure which shows one Embodiment of the tubular member which has various different cross-sectional shapes. The figure which shows one Embodiment of the tubular member which has various different cross-sectional shapes. FIG. 3 is a cross-sectional view of a catheter shaft including two intermediate elements.

Claims (18)

A method of manufacturing a medical device,
Disposing axially spaced first and second tubular portions, each defining a lumen extending therein, in a cavity at least partially defined by the mold;
Delivering a molten resin into a region of the mold between the first tubular member and the second tubular member; and when the resin is cured, the composition of at least one of the first and second tubular members; Forming an intermediate tubular member having a different composition;
Disposing a tip in the tip region of the medical device.   The method of claim 1, wherein the tip is secured to at least one of the first and second tubular members.   The method of claim 1, further comprising placing a mandrel in at least one of the lumens of the first and second tubular members.   The method of claim 1, wherein the mold defines at least one recessed region extending outwardly from the cavity and in communication with the cavity.   The method of claim 4, wherein the at least one recessed area comprises a groove extending circumferentially around the cavity.   The method of claim 4, wherein the recessed area comprises a spiral groove.   The method of claim 4, wherein the mold defines a plurality of recessed areas spaced axially along the mold.   The mold is configured to substantially prevent axial movement of the first and second tubular members relative to each other when the first and second tubular members are disposed within the mold. The method of claim 1, wherein:   The method of claim 1, wherein the resin has a melting temperature that is lower than a melting temperature of the first and second tubular members.   The method of claim 1, further comprising heating the mold to a temperature below the melting temperature of the first and second tubular members.   The method of claim 1, wherein the resin and at least one of the first and second tubular members are not thermally compatible.   The method of claim 1, wherein the intermediate tubular member has a hardness that is lower than a hardness of at least one of the first and second tubular members.   Further comprising removing material from at least one end region of each of the first and second tubular members, each of the end regions forming an acute angle with respect to the longitudinal axis of the medical device after material removal. The method of claim 1, comprising an extending surface.   The method of claim 1, further comprising chemically bonding the resin to at least one of the first and second tubular members.   The method of claim 1, wherein the first and second tubular members are not thermally compatible. A proximal tubular member;
A distal tubular member;
An intermediate tubular member joined to a distal end region of the proximal end side tubular member and joined to a proximal end region of the distal end side tubular member; and the intermediate tubular member includes at least one of the proximal end side and the distal end side tubular member A medical device comprising: at least one material that is not thermally compatible with one material.   The medical device of claim 16, further comprising a flexible tip tip secured to the tip region of the medical device.   The medical device of claim 16, wherein the intermediate tubular member comprises at least one raised feature extending from an outer surface of the intermediate tubular member.

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